Use of Viscous medium to study anthelmintic drug action in Caenorhabditis elegans.

Caenorhabditis elegans is an appealing tool for experimental evolution and for working with antiparasitic drugs, from understanding the molecular mechanisms of drug action and resistance to uncover new drug targets. We present a new methodology for studying the impact of antiparasitic drugs in C. elegans. Viscous medium was initially designed for C. elegans maintenance during long-term evolution experiments. Viscous medium provides a less structured environment than the standard nematode growth media agar, yet the bacteria food source remains suspended. Further, the Viscous medium offers the worm population enough support to move freely, mate, and reproduce at a rate comparable to standard agar cultures. Here, the Viscous medium was adapted for use in antiparasitic research. We observed a similar sensitivity of C. elegans to anthelmintic drugs as in standard liquid media and statistical difference to the standard agar media through a larval development assay. Using Viscous medium in C. elegans studies will considerably improve antiparasitic resistance research, and this medium could be used in studies aimed at understanding long-term multigenerational drug activity.

Identification of Indicator Genes for Agar Accumulation in Gracilariopsis lemaneiformis (Rhodophyta).

Agar, as a seaweed polysaccharide mainly extracted from Gracilariopsis lemaneiformis, has been commercially applied in multiple fields. To investigate factors indicating the agar accumulation in G. lemaneiformis, the agar content, soluble polysaccharides content, and expression level of 11 genes involved in the agar biosynthesis were analysed under 4 treatments, namely salinity, temperature, and nitrogen and phosphorus concentrations. The salinity exerted the greatest impact on the agar content. Both high (40‱) and low (10‱, 20‱) salinity promoted agar accumulation in G. lemaneiformis by 4.06%, 2.59%, and 3.00%, respectively. The content of agar as a colloidal polysaccharide was more stable than the soluble polysaccharide content under the treatments. No significant correlation was noted between the two polysaccharides, and between the change in the agar content and the relative growth rate of the algae. The expression of all 11 genes was affected by the 4 treatments. Furthermore, in the cultivar 981 with high agar content (21.30 ± 0.95%) compared to that (16.23 ± 1.59%) of the wild diploid, the transcriptional level of 9 genes related to agar biosynthesis was upregulated. Comprehensive analysis of the correlation between agar accumulation and transcriptional level of genes related to agar biosynthesis in different cultivation conditions and different species of G. lemaneiformis, the change in the relative expression level of glucose-6-phosphate isomerase II (gpiII), mannose-6-phosphate isomerase (mpi), mannose-1-phosphate guanylyltransferase (mpg), and galactosyltransferase II (gatII) genes was highly correlated with the relative agar accumulation. This study lays a basis for selecting high-yield agar strains, as well as for targeted breeding, by using gene editing tools in the future.

Agar-tragacanth/silk fibroin hydrogel containing Zn-based MOF as a novel nanobiocomposite with biological activity.

In this study, a novel nanobiocomposite consisting of agar (Ag), tragacanth gum (TG), silk fibroin (SF), and MOF-5 was synthesized and extensively investigated by various analytical techniques and basic biological assays for potential biomedical applications. The performed Trypan blue dye exclusion assay indicated that the proliferation percentage of HEK293T cells was 71.19%, while the proliferation of cancer cells (K-562 and MCF-7) was significantly lower, at 10.74% and 3.33%. Furthermore, the Ag-TG hydrogel/SF/MOF-5 nanobiocomposite exhibited significant antimicrobial activity against both E. coli and S. aureus strains, with growth inhibition rates of 76.08% and 69.19% respectively. Additionally, the hemolytic index of fabricated nanobiocomposite was found approximately 19%. These findings suggest that the nanobiocomposite exhibits significant potential for application in cancer therapy and wound healing.

Modeling the growth of Aspergillus brasiliensis affected by a nonthermal plasma.

AIM: The main objective of the study was to develop and validate a model for the growth of Aspergillus brasiliensis on surfaces, specifically on agar culture medium. An additional aim was to determine conditions for complete growth inhibition of this micromycete using two different nonthermal plasma (NTP) sources. METHODS AND RESULTS: The developed model uses two key parameters, namely the growth rate and growth delay, which depend on the cultivation temperature and the amount of inoculum. These parameters well describe the growth of A. brasiliensis and the effect of NTP on it. For complete fungus inactivation, a single 10-minute exposure to a diffuse coplanar surface barrier discharge was sufficient, while a point-to-ring corona discharge required several repeated 10-minute exposures at 24-h intervals. CONCLUSIONS: The article presents a model for simulating the surface growth of A. brasiliensis and evaluates the effectiveness of two NTP sources in deactivating fungi on agar media.

Development of smart colorimetric indicators for tracking kimchi freshness by loading aronia extract in agar, κ-carrageenan, and cellulose nanofiber films.

Color indicator films incorporating aronia extract powder (AEP) and biopolymers like agar, carrageenan, and cellulose nanofiber (CNF) were developed to monitor kimchi freshness. AEP-containing films showed strong UV-barrier properties, and reduced light transmittance by 99.12 % for agar, 98.86 % for carrageenan, and 98.67 % for CNF-based films. All AEP-films exhibited high sensitivity to pH changes and vapor exposure to ammonia and acetic acid. Color change notably influenced by the polymer type, particularly evident with ammonia vapor exposure, especially in the AEP/carrageenan film. The chemical structure and thermal stability of the biopolymers remained unchanged after AEP-addition. Tensile strength increased by 24.2 % for AEP/CNF but decreased by 19.4 % for AEP/agar and 24.3 % for AEP/carrageenan films. AEP-containing films displayed strong antioxidant activity, with 99 % free radical scavenging in ABTS and ~ 80 % in DPPH assays. Alkalized AEP-indicator films were more effective in detecting color changes during kimchi packaging tests. Among the labels, alkalized AEP/agar film showed the most obvious color change from green-gray (fresh kimchi, pH 5.5, acidity 0.48 %) to pale brown (optimal fermentation, pH 4.6, acidity 0.70 %), and pale violet-brown (over-fermented, pH 3.80, acidity 1.35 %). Alkalized AEP-indicator films offer promising real-time detection of packed fermented foods like kimchi.

Unique behavioral patterns of wandering colonies of Brevibacillus thermoruber on agar plates.

Brevibacillus thermoruber strain Nabari cells grow as widely spreading dendritic colonies on reasoner's 2A-agar (1.5%) plates at around 55°C but as small motile colonies at 37°C. Motile colonies can be divided into colonies that move in straight or curved lines over long distances (wandering colonies), and colonies that rotate at a fixed location (rotating colonies). The addition of surfactant to the agar medium greatly increased the frequency of wandering colonies and facilitated the study of such colonies. The morphology of the wandering colonies varied: circular at the tip and pointed at the back, lemon-shaped with pointed ends, crescent-shaped, bullet-shaped, fish-like, and so on. A single colony may split into multiple colonies as it moves, or multiple colonies may merge into a single colony. The most surprising aspect of the movement of wandering colonies was that when a moving colony collides with another colony, it sometimes does not make a U-turn, but instead retreats straight back, as if bouncing back. The migration mechanisms of wandering colonies are discussed based on optical microscopic observations of swimming patterns of single cells in water and scanning electron microscopy of the arrangement of bacterial cells in wandering colonies.

Evaluation of the Effect of Lactobacillus acidophilus ATCC 4356 Bacteriocin against Staphylococcus aureus.

Background: Lactobacillus acidophilus is lactic acid bacteria that produce bacteriocins. Bacteriocins are antimicrobial peptides or proteins that exhibit activity against closely related bacteria. The aim of this study was to determine the effect of L. acidophilus ATCC 4356 bacteriocin against Staphylococcus aureus. Material and Methods. We used four different phenotypic methods for antimicrobial activities against two standard strains: methicillin-resistant S. aureus (MRSA) ATCC 33591 and methicillin-susceptible S. aureus (MSSA) ATCC 25923. The methods were (1) agar well diffusion, (2) overlay soft agar, (3) paper disk, and (4) modification of punch hole. The ammonium sulfate method was used to concentrate crude bacteriocin, and ultrafiltration and dialysis tubes were used to remove ammonium sulfate from the bacteriocins. Each method was repeated in triplicate. Result: L. acidophilus ATCC 4356 showed antimicrobial activity against both MRSA and MSSA standard strains only by the overlay soft agar method and not by the agar well diffusion, punch hole modification, and paper disk methods. No antimicrobial effects were observed in crude bacteriocins concentrated. Conclusion: The growth inhibition of S. aureus in overlay soft agar method may be due to the production of bacteriocin-like substances. The overlay soft agar method is a qualitative test, so there is a need for further study to optimize the conditions for the production of bacteriocin-like substances in the culture supernatant and precise comparison between the inhibitory activity and pheromone secretion of different strains.

Cobalt complexes modulate plasmid conjugation in Escherichia coli and Klebsiella pneumoniae.

Antimicrobial resistance genes (ARG), such as extended-spectrum ß-lactamase (ESBL) and carbapenemase genes, are commonly carried on plasmids. Plasmids can transmit between bacteria, disseminate globally, and cause clinically important resistance. Therefore, targeting plasmids could reduce ARG prevalence, and restore the efficacy of existing antibiotics. Cobalt complexes possess diverse biological activities, including antimicrobial and anticancer properties. However, their effect on plasmid conjugation has not been explored yet. Here, we assessed the effect of four previously characterised bis(N-picolinamido)cobalt(II) complexes lacking antibacterial activity on plasmid conjugation in Escherichia coli and Klebsiella pneumoniae. Antimicrobial susceptibility testing of these cobalt complexes confirmed the lack of antibacterial activity in E. coli and K. pneumoniae. Liquid broth and solid agar conjugation assays were used to screen the activity of the complexes on four archetypical plasmids in E. coli J53. The cobalt complexes significantly reduced the conjugation of RP4, R6K, and R388 plasmids, but not pKM101, on solid agar in E. coli J53. Owing to their promising activity, the impact of cobalt complexes was tested on the conjugation of fluorescently tagged extended-spectrum ß-lactamase encoding pCTgfp plasmid in E. coli and carbapenemase encoding pKpQILgfp plasmid in K. pneumoniae, using flow cytometry. The complexes significantly reduced the conjugation of pKpQILgfp in K. pneumoniae but had no impact on pCTgfp conjugation in E. coli. The cobalt complexes did not have plasmid-curing activity, suggesting that they target conjugation rather than plasmid stability. To our knowledge, this is the first study to report reduced conjugation of clinically relevant plasmids with cobalt complexes. These cobalt complexes are not cytotoxic towards mammalian cells and are not antibacterial, therefore they could be optimised and employed as inhibitors of plasmid conjugation.

Survival of O157 and non-O157 shiga toxin-producing Escherichia coli in Korean style kimchi.

Korean style kimchi contaminated with Shiga toxin-producing Escherichia coli (STEC) O157:H7 was the cause of an outbreak in Canada from December 2021 to January 2022. To determine if this STEC O157:H7 has greater potential for survival in kimchi than other STEC, the outbreak strain and six other STEC strains (O26:H11, O91:H21, O103:H2, O121:H19, and two O157:H7) were inoculated individually at 6 to 6.5 log CFU/g into commercially sourced kimchi and incubation at 4 °C. At intervals of seven days inoculated and control kimchi was plated onto MacConkey agar to enumerate lactose utilising bacteria. The colony counts were interpreted as enumerating the inoculated STEC, since no colonies were observed on MacConkey agar plated with uninoculated kimchi. Over eight weeks of incubation the pH was stable at 4.10 to 4.05 and the STEC strains declined by 0.7-1.0 log, with a median reduction of 0.9 log. The linear rate of reduction of kimchi outbreak STEC O157:H7 was -0.4 log per 30 days (Slope Uncertainty 0.05), which was not significantly different from the other O157 and nonO157 STEC strains (P = 0.091). These results indicate that the outbreak was not due to the presence of strain better adapted to survival in kimchi than other STEC, and that STEC can persist in refrigerated Korean style kimchi with a minimal decline over the shelf-life of the product.

Comparative efficacy of difloxacin and nano-emulsion difloxacin as antibacterial agents against Salmonella enterica Serovar enteritidis in chickenss.

Background: Avian salmonellosis is a group of diseases caused by bacteria from the genus Salmonella with a negative impact on poultry, particularly chickens. In addition, salmonellosis is a global food-borne infection. Aim: The aim of this study was to evaluate the effect of nano-emulsion difloxacin (NED) and commercial difloxacin (CD) water supplement on broiler's growth, feed intake, and body weight, weight gain, growth rate, feed conversion ratio (FCR), and mortality rate (MR). The antibiotic sensitivity was determined both in-vivo and in-vitro for NED against Salmonella enterica Serovar enteritidis in chickens. Methods: 1500 one-day of age chicks were grouped into five groups as follows: group 1 (G1) control negative group, G2 control positive group (infected and not treated), G3 (infected and treated with CD, and G4 and G5 (infected and treated with NED at different doses). Samples, including the intestine, liver, and spleen were collected. Agar well diffusion test and minimum inhibitory concentrations were adopted. Histopathological lesions on different tissues were studied. During 35 days of the experiment, the feed intake, growth rate, growth gain, FCR, and MR were recorded daily. In addition, a variety of analytical techniques including transmission electron microscopic analysis, dynamic light scattering, UV-visible spectroscopy, and zeta-potential analysis were applied to characterize NED. Results: The agar well diffusion test indicated that NED was in-vitro effective against S. enteritidis isolates than CD. The minimum inhibitory concentration was recorded as NED inhibited bacterial growth till well 8 at a concentration of 0.78 µg/ml; on the other hand, the CD inhibited bacterial growth till well 6 at a concentration of 0.62 µg/ml. Growth performance and MRs in the groups treated with NED are significantly reduced. Conclusion: Treatment of broiler's drinking water with NED at doses of 0.5 and 1 ml instead of pure CD was able to enforce a new perspective, antibacterial efficacy, enhancing the productive performance, and reducing the MRs of broilers.

Characterization of gelling agents in callus inducing media: Physical properties and their effect on callus growth.

In plant tissue culture, callus formation serves as a crucial mechanism for regenerating entire plants, enabling the differentiation of diverse tissues. Researchers have extensively studied the influence of media composition, particularly plant growth regulators, on callus behavior. However, the impact of the physical properties of the media, a well-established factor in mammalian cell studies, has received limited attention in the context of plant tissue culture. Previous research has highlighted the significance of gelling agents in affecting callus growth and differentiation, with Agar, Phytagel, and Gelrite being the most used options. Despite their widespread use, a comprehensive comparison of their physical properties and their subsequent effects on callus behavior remains lacking. Our study provides insights into optimizing plant tissue culture media by analyzing the physical properties of gelling agents and their impact on callus induction and differentiation. We compared the phenotypes of calli grown on media composed of these different gelling agents and correlated them to the physical properties of these media. We tested water retention, examined pore size using cryo-SEM, measured the media mechanical properties, and studied diffusion characteristics. We found that the mechanical properties of the media are the only quality correlated with callus phenotype.

Using CHROMagar™ STEC medium exclusively does not recover all clinically relevant Shiga toxin-producing Escherichia coli in Aotearoa, New Zealand.

Diagnostic laboratories in Aotearoa, New Zealand (NZ) refer cultures from faecal samples positive for Shiga toxin genes to the national Enteric Reference Laboratory for isolation of Shiga toxin-producing Escherichia coli (STEC) for epidemiological typing. As there was variation in the culture media being referred, a panel of 75 clinical isolates of STEC, representing 28 different serotypes, was used to assess six commercially available media and provide guidance to clinical laboratories. Recommendations were subsequently tested for a 3-month period, where STEC isolations and confirmations were assessed by whole genome sequencing analysis against the culture media referred. CHROMagar™ STEC (CH-STEC; CHROMagar Microbiology, Paris, France) or CH-STEC plus cefixime-tellurite sorbitol MacConkey agar was confirmed inferior to CH-STEC plus blood agar with vancomycin, cefsulodin, and cefixime (BVCC). The former resulted in fewer STEC types (n = 18) being confirmed compared to those from a combination of CH-STEC and BVCC (n = 42). A significant (P < .05) association with an STEC's ability to grow on CH-STEC and the presence of the ter gene cluster, and eae was observed. Culturing screen positive STEC samples onto both CH-STEC and BVCC ensures a consistently higher recovery of STEC from all clinical samples in NZ than CH-STEC alone.

The comparative plastisphere microbial community profile at Kung Wiman beach unveils potential plastic-specific degrading microorganisms.

Background: Plastic waste is a global environmental issue that impacts the well-being of humans, animals, plants, and microorganisms. Microplastic contamination has been previously reported at Kung Wiman Beach, located in Chanthaburi province along with the Eastern Gulf of Thailand. Our research aimed to study the microbial population of the sand and plastisphere and isolate microorganisms with potential plastic degradation activity. Methods: Plastic and sand samples were collected from Kung Wiman Beach for microbial isolation on agar plates. The plastic samples were identified by Fourier-transform infrared spectroscopy. Plastic degradation properties were evaluated by observing the halo zone on mineral salts medium (MSM) supplemented with emulsified plastics, including polystyrene (PS), polylactic acid (PLA), polyvinyl chloride (PVC), and bis (2-hydroxyethyl) terephthalate (BHET). Bacteria and fungi were identified by analyzing nucleotide sequence analysis of the 16S rRNA and internal transcribed spacer (ITS) regions, respectively. 16S and ITS microbiomes analysis was conducted on the total DNA extracted from each sample to assess the microbial communities. Results: Of 16 plastic samples, five were identified as polypropylene (PP), four as polystyrene (PS), four as polyethylene terephthalate (PET), two as high-density polyethylene (HDPE), and one sample remained unidentified. Only 27 bacterial and 38 fungal isolates were found to have the ability to degrade PLA or BHET on MSM agar. However, none showed degradation capabilities for PS or PVC on MSM agar. Notably, Planococcus sp. PP5 showed the highest hydrolysis capacity of 1.64 ± 0.12. The 16S rRNA analysis revealed 13 bacterial genera, with seven showing plastic degradation abilities: Salipiger, Planococcus, Psychrobacter, Shewanella, Jonesia, Bacillus, and Kocuria. This study reports, for the first time of the BHET-degrading properties of the genera Planococcus and Jonesia. Additionally, The ITS analysis identified nine fungal genera, five of which demonstrated plastic degradation abilities: Aspergillus, Penicillium, Peacilomyces, Absidia, and Cochliobolus. Microbial community composition analysis and linear discriminant analysis effect size revealed certain dominant microbial groups in the plastic and sand samples that were absent under culture-dependent conditions. Furthermore, 16S and ITS amplicon microbiome analysis revealed microbial groups were significantly different in the plastic and sand samples collected. Conclusions: We reported on the microbial communities found on the plastisphere at Kung Wiman Beach and isolated and identified microbes with the capacity to degrade PLA and BHET.

[Conventional paraffin embedding technique and double-embedding technique for minute oral biopsies and delicate pulp tissue - a comparative study]. / Traditsionnyi metod zalivki v parafin i metod dvoinoi zalivki dlya malen'kikh bioptatov polosti rta i myagkikh tkanei pul'py ­ sravnitel'noe issledovanie.

BACKGROUND: Among oral biopsies, small incisional tissues, have to be preserved all through the processing and embedding to ensure optimal visualization of all the mucosal layers without compromise. Optimal tissue orientation is the most critical step in tissue processing for demonstration of definitive morphology in the sections, which is often more challenging in cases of minute/small or thinner sections using routine paraffin techniques to evaluate accurate diagnosis. Some modification is needed to handle these samples to get a better result. Double embedding technique with some modification has been widely used for small/ thin/ multiple biopsies and gives excellent results in many other fields like general pathology and biotechnology. The double embedding technique though produced excellent and significant results in mucosal biopsies yet, it is of minimal interest among oral pathologists. To best of our knowledge, this is the first study to use double embedding technique for pulp tissues. OBJECTIVE: The present study was aimed to evaluate and compare the ease of embedding and sectioning sections using Agar-Paraffin double embedding technique for small oral mucosal biopsies and thin pulp tissues. MATERIAL AND METHODS: A total of 40 oral tissue samples categorized into two groups were taken for the present study. Group I included 20 small oral mucosal biopsy samples of size ranging from 0.2 to 0.5 cm and Group II included 20 pulp tissues obtained from freshly extracted non carious tooth. 10 blocks were prepared by routine paraffin method and 10 blocks were prepared by modified double embedding method for each group. Scores were given by comparing all the criteria with that of the routine paraffin technique. Chi-square test was used for statistical analysis. RESULTS: The average ease score for the Agar-Paraffin double embedded small/minute biopsies showed better scores than the pulp tissue with that of the routine technique. However, no statistically significant difference was seen among embedding and sectioning sections between the two groups. CONCLUSION: Modified double embedding method is simple and reliable alternative technique that helps in better orientation, processing and sectioning especially for oral small or thin biopsies and delicate pulp tissues.

Antibiotic resistance patterns of Staphylococcus aureus and Enterobacteriaceae isolated from street foods in selected towns of Ethiopia.

BACKGROUND: Street foods are any foods or drinks prepared or sold by street vendors in an open space. The purpose of this study was to determine the Bacteriological safety and antibiotic resistance patterns of Staphylococcus aureus and Enterobacteriaceae isolated from street foods. METHOD: A laboratory-based cross-sectional study was used from December 2022 to February 2023 on street foods of Addis Ababa, Hawassa, Dire Dawa, and Jimma towns of Ethiopia. 525 street foods and 175 water samples were taken from 175 street food vending stalls. Proportional allocation to the total town population and stratified sampling techniques were used to select vending stalls. Samples were analyzed for the presence of bacteria following the standard microbiological methods used for the isolation, enumeration, and identification of bacteria. Pour plate technique was used to transfer the suspension to MacConkey agar, Mannitol Salt Agar, and Salmonella Shigella Agar. The antibiotic susceptibility test was performed using the Kirby-Bauer disk diffusion method. SPSS software was used to analyze the data. RESULT: Out of 525 food samples, 279 (53%) were contaminated by bacteria. From 175 water samples, 95 (54.3%) were contaminated with Escherichia coli. From both samples in total, eleven bacterial species were isolated. Staphylococcus aureus was the most frequently isolated species. Shigella, Klebsiella, and Salmonella group A have statistically significant with the type of food. Erythromycin (54%), Streptomycin (17%), and Amoxicillin (14%) were the most resistant antibiotics. Least resistance was observed to Ciprofloxacin (5%). CONCLUSION: Street foods of the selected towns were highly contaminated with various antibiotic-resistant organisms. Hence, the relevant authorities ought to ensure the proper handling of street food by enforcing safety measures. Additionally, they should initiate a widespread awareness campaign promoting the prudent use of antibiotics among both street food vendors and the broader population.

Real-time monitoring of pork freshness using polyvinyl alcohol/modified agar multilayer gas-sensitive labels.

Accurate consumer perception of food packages should provide real-time feedback on any changes inside food packaging. Hence, a new multilayer gas-sensitive label (POA-12) was prepared using a layer-by-layer pouring method for simple, visual, and real-time detection of pork's freshness, while the front side was developed by immobilizing red carbon dots and fluorescein isothiocyanate in POA as indicator for volatile nitrogen, and the back side was created using bromothymol blue in POA as pH indicator. The swelling index of the multilayer gas-sensitive labels reduced from 159.19% to 148.36%, and the tensile strength increased from 25.52 MPa to 42.61 MPa. In addition, the POA-12 multilayer label showed a red-to-yellow fluorescence change as TVB-N increased from 6.84 to 31.4 and a yellow-brown-to-blue-green color change as pH increased from 5.74 to 7.24 when detecting pork samples. Thus, it provides dual-indicator monitoring that improves the accuracy and reliability of assessing the freshness of high-protein products.

Chitosanase-immobilized magnetite-agar gel particles as a highly stable and reusable biocatalyst for enhanced production of physiologically active chitosan oligosaccharides.

A novel immobilized chitosanase was developed and utilized to produce chitosan oligosaccharides (COSs) via chitosan hydrolysis. Magnetite-agar gel particles (average particle diameter: 338 µm) were prepared by emulsifying an aqueous agar solution dispersing 200-nm magnetite particles with isooctane containing an emulsifier at 80 °C, followed by cooling the emulsified mixture. The chitosanase from Bacillus pumilus was immobilized on the magnetite-agar gel particles chemically activated by introducing glyoxyl groups with high immobilization yields (>80%), and the observed specific activity of the immobilized chitosanase was 16% of that of the free enzyme. This immobilized chitosanase could be rapidly recovered from aqueous solutions by applying magnetic force. The thermal stability of the immobilized chitosanase improved remarkably compared with that of free chitosanase: the deactivation rate constants at 35 °C of the free and immobilized enzymes were 8.1 × 10-5 and 3.9 × 10-8 s-1, respectively. This immobilized chitosanase could be reused for chitosan hydrolysis at 75 °C and pH 5.6, and 80% of its initial activity was maintained even after 10 cycles of use. COSs with a degree of polymerization (DP) of 2-7 were obtained using this immobilized chitosanase, and the product content of physiologically active COSs (DP ≥ 5) reached approximately 50%.

Gelatin/agar pH-indicator film based on cranberry extract loaded with linalool nanoparticle: Survey on physical, antimicrobial, and antioxidant properties.

In this study, linalool-nanoparticles (L-NPs) were prepared (encapsulation efficiency was 68.54 %) and introduced pH-indicator film based on cranberry-extract (CEF) to develop multifunctional smart films. XRD analysis and FTIR spectroscopy indicated that cranberry-extract (CE) and L-NPs were uniformly distributed in the gelatin/agar matrix and could change the intermolecular structure of the film. Color change of smart films showed that CE endowed the film with pH-sensitive property. As CE and L-NPs were added to the film, the water contact angle (WCA) was increased from 57.03° to 117.73°, the elongation at break (EAB) was increased from 12.30 % to 34.60 %. Additionally, the introduction of L-NPs enhanced the antioxidant activity (DPPH free radical scavenging rate increased from 26.80 % to 36.35 %) and antibacterial activity (against S. aureus and E. coli) of the smart film, which were verified by its retarding effect on pork spoilage.

Premise setting for sustainable developing adsorption in environmental remediation using graphitic carbon nitride@agar-derived porous carbon composite.

In the adsorption process for wastewater treatment, the adsorbent plays an important role. A composite adsorptive material composed of graphitic carbon nitride and agar-derived porous carbon (CNPC) was fabricated from simple precursors (melamine, thiourea, and agar) and through a facile procedure with different melamine and thiourea ratios. Characterization of CNPC proved a successful formation of a porous structure consisting of mesopores and macropores, wherein CNPC holds distinctive electrochemical (lowered resistance and higher specific capacity) and photochemical properties (lowered bandgap to 2.33 eV) thanks to the combination of graphitic carbon nitride (CN) and agar-derived porous carbon (PC). Inheriting the immanent nature, CNPC was subjected to the adsorption of methylene blue (MB) dye in an aqueous solution. The highest adsorption capacity was 133 mg/g for CNPC-4 which was prepared using a melamine to thiourea ratio of 4:4 - equivalent to the removal rate of 53.2 % and following the pseudo-I-order reaction rate. The effect of pH points out that pH 7 and 9 were susceptible to maximum removal and pretreatment is not required while the optimal ratio of 7.5 mg of MB and 30 mg of material was also determined to yield the highest performance. Furthermore, the reusability of the material for three consecutive cycles was evaluated based on two methods pyrolysis at 200 °C and photocatalytic degradation by irradiation under visible light. In general, the photocatalytic regeneration pathway is more ample and efficient than pyrolysis in terms of energy efficiency (saving energy over 10 times) and adsorption capacity stability. As a whole, the construction of accessible regenerative and stable adsorbent could be a venturing step into the sustainable development spearhead for industries.

Fabrication, structure, characterization and emulsion application of citrate agar.

In this study, citric acid successfully reacted with agar through the dry heat method, and citrate agar (CA) gel was used to stabilize O/W emulsions. The mechanisms of the CA structure and emulsion pH that affected emulsion stabilization were analyzed, and the application of CA gel emulsion (CAGE) was explored. Compared with native agar (NA), CA showed lower gel strength, higher transparency, and higher water contact angle. These changes indicate that a cross-linking reaction occurred, and it was demonstrated via FTIR and NMR. The emulsion properties were evaluated using particle size, ζ-potential, and the emulsification activity index. Results showed that CAGEs had a smaller particle size and lower ζ-potential than the native agar gel emulsion (NAGE). Meanwhile, confocal laser scanning microscopy confirmed that the CA gels stabilized the emulsions by forming a protective film around the oil droplets. Stability experiments revealed that CAGE (prepared with CA gel [DS = 0.145]) exhibited better stability than NAGE in the pH range of 3-11, and the rheological results further confirmed that the stability of the emulsions was influenced by the network structure and oil droplet interaction forces. Afterward, the application prospect of CAGE was evaluated by encapsulating vitamin D3 and curcumin.